: While biologically human (conceived in the Time Vortex), medical scans in this episode suggest River may have two hearts , mirroring Time Lord physiology. Episode Significance River Song | Tardis - Doctor Who Wiki
: After seeing the Doctor’s kindness and learning about her parents' love for her, River uses all her remaining regeneration energy to bring him back to life, becoming fully human in the process. Character Revelations
: Amy and Rory's childhood friend Mels is revealed to be their daughter, Melody Pond . After being shot by Hitler (who is promptly shoved into a cupboard), Mels regenerates for the first time on-screen, becoming the woman known as River Song .
